I happened to work on a project hosted on Azure. The project made use of Entity Framework, and after a point I had to add migrations. But for some reason, the
update-database failed on the server with the following error:
Tables without a clustered index are not supported in this version of SQL Server. Please create a clustered index and try again.
The weird part was that every table had a clustered index, but it still wasn't working.
Apparently the clustered index requirement is a limitation in the Azure SQL Server Databases. These limitations don't exist in v12 and I could easily fix it by upgrading the SQL Server Version. There's an upgrade how-to at the Microsoft Azure site here.